Japanese Patent No. 2990646 proposes use of a composition comprising a straight chain fluoro polyether compound having at least two alkenyl groups and also having a perfluoropolyether structure in the backbone in one molecule, a fluorine-containing organohydrogensiloxane having at least two hydrogen atoms directly bonded to the silicon atom in one molecule, and a platinum group compound for the production of a cured product having well balanced heat resistance, chemical resistance, solvent resistance, releasability, water repellency, oil repellency, and low temperature properties.
Japanese Patent No. 3239717 proposes a composition having organopolysiloxane having hydrosilyl group and epoxy group and/or a trialkoxysilyl group added to the composition of the Japanese Patent No. 2990646 in order to provide the composition with self adhesive property with the metal or plastic substrate. This adhesive composition can be cured by heating, and the resulting cured article has improved features as described above and this composition can be used for adhesion application in various industrial fields such as electrical and electronic parts and parts mounted on motor vehicles.
However, heating to a high temperature of 100 to 200° C. is necessary for realizing adhesion of such adhesive composition to the metal, inorganic, and plastic substrates. Accordingly, when the substrate is a thermoplastic resin having a low heat resistance, changes in the shape and quality is induced by the heating. Also, use of such adhesive composition had limitation for the parts with the size that can not fit in the furnace. Furthermore, heating at such high temperature was disadvantageous in view of the energy cost of the furnace, and also, in environmental view of the amount of the carbon dioxide discharged from the furnace.
In view of the situation as described above, Japanese Patent Application Laid-Open No. 2008-291142 proposes further addition of a compound having at least two allyl oxycarbonyl group (CH2═CHCH2OC(═O)—) in one molecule to the adhesive composition as described above for the purpose of developing adhesive properties to the metal or plastic substrate by a heat treatment of up to 100° C.
This improvement realized excellent initial adhesion. However, when the composition is left at a relatively high temperature below 100° C., for example, at 80° C., for a long time, the composition suffered from the problem of substantial loss in the adhesiveness. For use in the application around electrical and electronic parts and parts mounted on motor vehicles, the adhesive is required to have an adhesion durability such that the adhesion would be maintained under such temperature conditions.